I have a (nearly) 4 week old boy who, the in the last couple of days has become a bit of a nightmare. I'm combination feeding on demand but he's not sleeping during the day/at night after feeds like he did for the first 3 weeks. Im conscious he's becoming over tired which is why he's grouchy. We've tried taking him for walks, ensuring the room is dark and bathing but he's extremely restless and doesn't want to sleep! What can I do? The sleepless nights/days are becoming unmanageable!